Eating dark chocolate may have health benefits such as raising antioxidant levels in the bloodstream and lowering levels of bad cholesterol, according to European researchers.

Researchers at the Rome Institute for Food and Nutrition Research measured the antioxidant levels of 12 volunteers one hour after they had eaten chocolate. Eating one hundred grams of plain chocolate boosted volunteers' antioxidant levels by almost 20%, while eating milk chocolate or drinking milk while eating plain chocolate did not have the same effect, reported Agence France-Presse.

"Our findings indicate that milk may interfere with the absorption of antioxidants from chocolate...and may therefore negate the potential health benefits that can be derived from eating moderate amounts of plain chocolate," the researchers said. 

Co-author Alan Crozier, of the University of Glasgow, said that people should be aware that dark chocolate still contains large amounts of fat and sugar.

"Don't think by eating five or six bars a day you're doing yourself any good," he was quoted by Dow Jones News as saying.

Meanwhile, research from Germany, published in the Journal of the American Medical Association, has suggested that eating dark chocolate could lower blood pressure.

Researchers studied adults with untreated mild hypertension who ate a three-ounce chocolate bar each day for two weeks. Half the subjects were given white chocolate, while the rest had dark chocolate.

Those who ate the white chocolate bars were found to have little change in blood pressure after two weeks, while the blood pressure of those who ate dark chocolate was lower.

Research has shown that cocoa contains flavonoids, which are antioxidants and may also lower LDL cholesterol, reported Dow Jones International News.